Thermo-mechanical characterisation of AA 6056-T4 and estimation of its material properties using Genetic Algorithm

This paper presents an experimental investigation of thermo-mechanical material properties of AA 6056-T4, which is used extensively in aeronautic applications. Monotonic tensile tests have been carried out on the dog-bone type specimens at temperatures ranging from room temperature (16 degrees C) to high temperature (450 degrees C) with two different strain rates; viz, high strain rate (similar to 0.002 s(-1)) and low strain rate (similar to 0.0002 s(-1)). Specimens were heated with the help of Joule heating system using Gleeble (R) 3500 machine at a temperature rate of 25 degrees C/s. Material properties which were investigated include the Young's modulus, yield strength at 0.1% plastic strain and hardening modulus. Estimation of material properties using Genetic Algorithm is introduced in the second part of the paper. This approach is incorporated to suggest the model for material properties in terms of temperature and strain rate. The suitability of the proposed model is evaluated using experimental data. Having established a reasonable comparison with experimental results, the material properties are predicted with consistent strain rate values. (C) 2010 Elsevier Ltd. All rights reserved.